1. Field of the Invention
The present invention relates to a method for making carbon fabrics, more particularly, to such a method for making carbon fabrics having high conductivity with high magnetic wave shielding efficiency by carbonizing a woven fabric, which is made by using oxidized fibers of polypropylene as raw materials, and by keeping the shrinkage of the fabric controlled below 30%.
2. Description of the Related Art
Conventional carbon fabrics are commonly formed of carbon fiber bundles by weaving. Because carbon fibers are fragile, it is not practical to directly weave carbon fibers into fabrics. Further, carbon fabrics directly woven from carbon fibers have a loose structure with big gaps in carbon fiber bundles. Therefore, regular carbon fabrics are not suitable for use to shield magnetic waves directly.
However, oxidized fibers, which are the raw material for making carbon fibers, are soft fibers having extensibility over 10%. Through a special heat treatment, fabrics of oxidized fibers can be processed into carbon fabrics of high conductivity high conductivity with high magnetic wave shielding efficiency.